1. Field of the Invention
This invention relates to means for regulating the temperature of temperature-sensitive instrumentation equipment. The invention is, for example, well adapted for use with chromatographic apparatus, wherein a sample fluid is injected into a column to be separated into its individual components which elute successively from the column to permit measurement of the concentration thereof.
2. Description of the Prior Art
Chromatographic apparatus is known to be quite temperature sensitive, particularly the separation columns commonly used in such apparatus. Thus, when accurate component concentration measurements are desired, such apparatus usually has been provided with temperature-regulating means to hold the equipment temperature within a quite narrow range. Although a variety of different approaches have been proposed for achieving this result, generally the temperature-sensitive chromatographic elements have been placed in a chamber arranged as an oven, with electrical heating means to elevate the temperature above ambient, and with one or more electrically-operated thermostats to control the rate of heat generation so as to regulate the temperature of the chromatographic apparatus.
Such electrical heating and temperature-regulating systems are undesirable for use in process chromatographs, in large part because the introduction of electrical energy in the process area creates potentially serious hazards. Thus, there has been a need for non-electrical heating and temperature-regulating means adapted for use with chromatographic apparatus. Moreover, there is a need for such apparatus which is relatively simple, reliable in operation, and economical to manufacture.